A medieval wizard, Gregory the Smarmy invented Gregory's Unctuous Unction, a potion that makes the drinker think whomever gave the potion is his or her best friend. Gregory allegedly wormed his way into King Richard's confidence with this potion and thus made his fortune.

Behind his chipped statue used to be a secret passageway outside the school, which was found by Fred and George Weasley during their first week of school and which caved in during the Battle of Hogwarts. The statue has since been used as a landmark on the fifth floor corridor.